China's share of the world's combined gross output rose to 6 percent at the end of 2007, compared with just 1.8 percent in 1978 when its reform and opening-up began, the National Bureau of Statistics (NBS) announced on Monday.

Fast economic growth over the last 30 years had lifted China's GDP ranking in the world from 10th in 1978 to fourth after the United States, Japan and Germany.

It stood at $3.28 trillion in 2007, about 23.7 percent of that of the US, 74.9 percent of Japan's and 99.5 percent of Germany's, said an NBS statement on its report on China's development since 1978.

By the World Bank rankings, China was a developing economy falling into the category of lower middle income, with per capita income ranging between $936 and $3,705.

Per capita income jumped to $2,360 in 2007 from $190 in 1978, the NBS statement said.

According to the bureau, the past 30 years witnessed a significant change in the country's comprehensive national strength and international influence thanks to the reform and opening-up policy.

China's GDP grew at an annual average rate of 9.8 percent from 1979 to 2007, higher than the annual average rate of 6.1 percent from 1953 to 1978.

The economic growth rate in the past three decades was also much higher than the world average, and slightly higher than Japan's 9.2 percent and South Korea's 8.5 percent during their economic takeoff periods.

But China still faced a number of major economic and social problems, as its market system is far from perfect, its growth pattern and structural problems need to be changed for the better, the statement said.

China's rural areas and agriculture remained an urgent problem for the country's coordinated development.